Underfloor heating is a popular and efficient way to keep homes cosy during Edinburgh’s long, chilly winters. Whether you live in a Victorian flat in Morningside or a modern development in Leith, underfloor heating offers discreet warmth and energy savings. However, like any home system, it’s not immune to occasional problems.
In this article, we’ll walk you through the five most common underfloor heating issues that Edinburgh homeowners face—and what you can do to fix them. We’ll also help you understand when it’s safe to tackle a problem yourself and when it’s best to call in the professionals.
1. Uneven or Patchy Heating
Symptoms:
You notice that one part of the floor is toasty while another section remains cold. In some rooms, the heat may be barely noticeable at all.
Possible Causes:
- Airlocks in hydronic (water-based) systems
- Broken or damaged cables in electric systems
- Faulty zone controls or thermostats
- Incorrect floor insulation allowing heat loss in certain areas
DIY Solutions:
- Bleed the system (for wet systems): Air trapped in pipes can prevent water from circulating. You can try bleeding individual loops if your manifold allows it.
- Check thermostat settings: Ensure the thermostat is calling for heat and hasn’t been accidentally turned off or programmed incorrectly.
- Inspect insulation (if accessible): Poor insulation under floors can lead to heat escaping rather than rising into the room.
When to Call a Professional:
- Persistent cold spots, even after bleeding the system
- Suspected damage to underfloor heating cables or pipework (which may require thermal imaging or lifting the floor)
- Zoned heating issues that suggest a control unit or wiring fault
2. Thermostat Not Responding or Malfunctioning
Symptoms:
Your heating system doesn’t respond to changes in the thermostat. It may not turn on at all, or the room fails to reach the desired temperature.
Possible Causes:
- Dead batteries in the thermostat (for wireless models)
- Loose or damaged wiring
- Faulty temperature sensors
- Incorrect configuration or software issues in smart thermostats
DIY Solutions:
- Replace batteries: An easy first step that often solves the problem
- Reset the thermostat: Refer to the manufacturer’s manual for specific instructions
- Replace the thermostat: If confident and competent, you can replace a faulty thermostat with a like-for-like model, especially in electric systems
When to Call a Professional:
- If the thermostat continues to malfunction after basic checks
- If you’re unsure about handling electrical components
- If a smart thermostat is miscommunicating with your heating system (which may involve both hardware and app-level troubleshooting)
3. Leaks in Hydronic (Water-Based) Systems
Symptoms:
- A drop in boiler pressure
- Damp patches appearing on flooring
- Musty smells or visible signs of moisture
- Heating inefficiency or failure
Causes:
Leaks can occur due to:
- Pipe degradation (especially if older systems were poorly installed)
- Weak pipe joints or fittings
- Floor movement or wear-and-tear causing pipe damage
DIY Solutions (Temporary Only):
- Turn off the water supply to prevent further damage
- Drain the system, if necessary, to avoid leaks worsening
- Isolate zones if your system allows, to minimise disruption
However, in nearly all cases, this is where DIY ends.
Professional Solutions:
- Use of thermal imaging cameras to locate the exact source of the leak
- Careful floor lifting and repair or replacement of the damaged pipe
- System pressure testing and rebalancing after the fix
Edinburgh Note:
Older homes with timber or stone flooring require extra care—water damage can lead to long-term structural or insulation issues. Quick action is essential.
4. System Not Heating at All
Symptoms:
- No warmth throughout the home
- System remains cold despite the thermostat calling for heat
- Boilers or heating units may display fault codes or warnings
Possible Causes:
- Tripped circuit breakers or blown fuses
- Faulty pumps in wet systems
- Disconnected wiring in electric mats
- Central control unit issues
DIY Checks:
- Check your fuse box: A tripped circuit breaker may be to blame
- Reset the system: Many systems have a reset function—check the manual
- Inspect thermostats: Make sure they’re on and correctly set
When to Call a Professional:
- If fuses repeatedly blow or the system trips breakers frequently
- If there are no signs of heat despite the system being powered
- When pumps or valves in wet systems fail (which usually requires specialised tools and parts)
5. High Energy Bills or Reduced Efficiency
Symptoms:
- Heating bills have gone up noticeably
- Rooms take much longer to heat up
- Floor feels cooler than it used to
Possible Causes:
- Thermostat is placed near heat sources or draughts, causing inaccurate readings
- The system is overworked due to heat loss or poor scheduling
- Insufficient floor insulation
- Build-up of air or sludge in wet systems, reducing flow
DIY Solutions:
- Reposition thermostats away from windows or radiators
- Optimise your heating schedule: Use lower, consistent temperatures over longer periods
- Use floor coverings wisely: Thick rugs can block heat
- If accessible, improve floor insulation under ground floors or in extensions
Professional Solutions:
- Full system audit and balancing
- Addition of smart controls or zoning
- Flushing or descaling hydronic systems to remove sludge and improve flow
| Problem | DIY Fix Possible? | Professional Needed? |
| Uneven heating | ✅ Yes (bleed or reset) | ✅ If persistent |
| Thermostat not responding | ✅ Battery/setting check | ✅ For rewiring |
| Leak in water-based system | ❌ Emergency shut-off only | ✅ Yes |
| Entire system not heating | ✅ Basic electrical checks | ✅ If unclear |
| High energy bills / inefficiency | ✅ Insulation & schedule | ✅ For system audit |
Conclusion
Underfloor heating is one of the most efficient and comfortable ways to heat your home—but like all systems, it needs the occasional bit of TLC. Fortunately, most common issues are easy to spot and, in some cases, even easier to fix.
If you’re confident with basic tools and understand your system, you may be able to resolve simple problems like bleeding radiators or replacing thermostats on your own. But for anything involving leaks, wiring, or diagnostics beneath your flooring—don’t risk it. Hiring a qualified heating engineer in Edinburgh not only keeps your home safe, but it can also save money in the long run.
Final Tip
Want to avoid issues altogether? Consider booking a yearly service before winter hits. A heating professional can catch small faults early—saving you from a chilly surprise when you need warmth the most.